Total Reflection X-ray Fluorescence Research Articles

Synthesis and Characterization of (CdO- CuOCo3O4) Mixed Metal Oxides Nanocomposite

Synthesis and Characterization of (CdO- CuOCo3O4) Mixed Metal Oxides Nanocomposite

Development of a cascade impactor optimized for size-fractionated analysis of aerosol metal content by total reflection X-ray fluorescence spectroscopy (TXRF)

Development of a cascade impactor optimized for size-fractionated analysis of aerosol metal content by total reflection X-ray fluorescence spectroscopy (TXRF)

Effects of surface property on loading octaaza bis-α-diimine Ni complex, charge separation, and H2 production activity of MnS@ZnS photocatalysts

The MnS@ZnS photocatalyst was prepared using a microwave-assisted solvothermal method. Then, the octaaza bis-α-diimine Ni complex was loaded to prepare a composite photocatalyst. The adsorption of metal complex on photocatalyst depends on the anchoring groups of the Ni complex and the colloidal surface charge of the photocatalyst. The effects of the zeta potential of MnS and MnS@ZnS photocatalysts on the loading of Ni complex, separation of photogenerated carriers, and activity of Ni complex-modified composite photocatalysts were studied. The loading of NiC complex in photocatalysts was analyzed by Raman spectra, TEM line scan, mapping images, and total reflection x-ray fluorescence spectrometer. MnS@ZnS photocatalyst exhibits negative zeta potential that provides a strong electrostatic attraction force between photocatalysts and the Ni complex (Columb attraction), leading to increased Ni complex loading. MnS@ZnS/Ni complex exhibits better photocatalytic activity than MnS/Ni complex. Loading the Ni complex facilitates the photosensitization of photocatalysts, resulting in improved light absorbance. Besides, the electron-hole separation was further improved because the Ni complex acted as a redox mediator, enabling the transfer of electrons from MnS@ZnS to the Ni complex. The H2 production activity of MnS@ZnS/Ni complex photocatalyst reaches 3997 μmol h−1g−1, which is 1.72 times the pristine MnS.

Quantifying salivary iodine biomarker using total reflection X-ray fluorescence (TXRF): A method for assessing and monitoring iodine status simulated by Monte Carlo

Iodine stands as a vital trace element essential crucial for synthesizing thyroid hormones, which are essential for regulating metabolism and tissue growth. The “gold standard” for assessing iodine status in a population quantifies the iodine content in urine samples and is based on Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). Such method, or methods involving the readings of the Sandell-Kolthoff (SK) reaction, require complex sample preparations and the use of several toxic chemical elements. However, recent studies have shown a strong correlation between urinary iodine content (UIC) and iodine present in saliva. Using Monte Carlo simulations, this paper presents a TXRF-based method to quantify salivary iodine biomarker for assessing and monitoring iodine status. In the theoretical analysis, mono and polychromatic (filtered) excitation sources are considered. The detection and quantification limits of iodine, as well as the calibration curves for mass recovery, used the strong I Kα1 and I Kα2 lines. It was found that the optimal X-ray excitation source energy for iodine detection is 50 keV monochromatic X-rays. In contrast, using simulated spectra from a tungsten anode target, the best result was found at 70 kVp (peak voltage), after filtering the white beam with a copper absorber. Detection limits of iodine are 0.121 ng and 2.292 ng, for mono and polychromatic sources, respectively. The theoretical results of this paper show that TXRF could be a fast, simple and accurate alternative to ICP-MS or SK reaction-based methods. Of clinical significance, quantifying salivary iodine using TXRF to assess and monitor iodine status could be particularly helpful to patients undertaking 131I treatment. In addition, it could be used in epidemiological field studies to determine iodine deficiency/excess in children and pregnant women.

Quantification of [99Tc]TcO4- in urine by means of anion-exchange chromatography–aerosol desolvation nebulization–inductively coupled plasma–mass spectrometry

To sensitively determine 99Tc, a new method for internal quantification of its most common and stable species, [99Tc]TcO4-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{O}}_{4}^{-}$$\\end{document}, was developed. Anion-exchange chromatography (IC) was coupled to inductively coupled plasma–mass spectrometry (ICP-MS) and equipped with an aerosol desolvation system to provide enhanced detection power. Due to a lack of commercial Tc standards, an isotope dilution-like approach using a Ru spike and called isobaric dilution analysis (IBDA) was used for internal quantification of 99Tc. This approach required knowledge of the sensitivities of 99Ru and 99Tc in ICP-MS. The latter was determined using an in-house prepared standard manufactured from decayed medical 99mTc-generator eluates. This standard was cleaned and preconcentrated using extraction chromatography with TEVA resin and quantified via total reflection X-ray fluorescence (TXRF) analysis. IC coupled to ICP-MS enabled to separate, detect and quantify [99Tc]TcO4-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{O}}_{4}^{-}$$\\end{document} as most stable Tc species in complex environments, which was demonstrated in a proof of concept. We quantified this species in untreated and undiluted raw urine collected from a patient, who previously underwent scintigraphy with a 99mTc-tracer, and determined a concentration of 19.6 ± 0.5 ng L−1. The developed method has a high utility to characterize a range of Tc-based radiopharmaceuticals, to determine concentrations, purity, and degradation products in complex samples without the need to assess activity parameters of 99(m)Tc.Graphical

Statistical analysis of analytical results near detection limits with illustrations using elemental determinations in medical and biological samples by total reflection X-ray fluorescence

The following paper presents statistical analysis of measurement results close to the detection limit of an analytical technique and being random-left censored data. For such observations the measured value is not known precisely but is restricted by the detection limit. In the paper, the idea of random-left censored observations and data analysis are presented generally and next it is shown how to include censored observations into the statistical analysis with the use of available statistical analysis software (survival analysis procedure). Statistical procedure is presented on the examples of the X-ray spectroscopic analysis of element concentrations in medical and biological samples. Censored observations are included in data analysis and quartiles are estimated. Additionally, two- and multigroup comparison is presented for the censored observations. The accuracy of the presented procedure is demonstrated and discussed on the basis of Monte-Carlo simulations.

Glioblastoma multiforme influence on the elemental homeostasis of the distant organs: the results of inter-comparison study carried out with TXRF method

Glioblastoma (GBM) is a fast-growing and aggressive brain tumor which invades the nearby brain tissue but generally does not spread to the distant organs. Nonetheless, if untreated, GBM can result in patient death in time even less than few months from the diagnosis. The influence of the tumor progress on organs other than brain is obvious but still not well described. Therefore, we examined the elemental abnormalities appearing in selected body organs (kidney, heart, spleen, lung) in two rat models of GBM. The animals used for the study were subjected to the implantation of human GBM cell lines (U87MG and T98G) characterized by different levels of invasiveness. The elemental analysis of digested organ samples was carried out using the total reflection X-ray fluorescence (TXRF) method, independently, in three European laboratories utilizing various commercially available TXRF spectrometers. The comparison of the data obtained for animals subjected to T98G and U87MG cells implantation showed a number of elemental anomalies in the examined organs. What is more, the abnormalities were found for rats even if neoplastic tumor did not develop in their brains. The most of alterations for both experimental groups were noted in the spleen and lungs, with the direction of the found element changes in these organs being the opposite. The observed disorders of element homeostasis may result from many processes occurring in the animal body as a result of implantation of cancer cells or the development of GBM, including inflammation, anemia of chronic disease or changes in iron metabolism. Tumor induced changes in organ elemental composition detected in cooperating laboratories were usually in a good agreement. In case of elements with higher atomic numbers (Fe, Cu, Zn and Se), 88% of the results were classified as fully compliant. Some discrepancies between the laboratories were found for lighter elements (P, S, K and Ca). However, also in this case, the obtained results fulfilled the requirements of full (the results from three laboratories were in agreement) or partial agreement (the results from two laboratories were in agreement).

Evaluations of the optimal plasma treated area in total reflection X-ray fluorescence analysis and the retention period of superhydrophilic ability of the substrate

An atmospheric pressure plasma jet was applied to control the form of a dried residue for total reflection X-ray fluorescence analysis.

Monitoring of toxic metals and metalloids in the urine of non‐professional sportsmen using total reflection x‐ray fluorescence

AbstractExposure to toxic metals and metalloids is a significant public health concern and can seriously affect human health. The aim of this study was to establish the presence of toxic metals and metalloids in the urine of non‐professional sportsmen who participated in a mountain ultramarathon using a benchtop total reflection x‐ray fluorescence (TXRF) system. TXRF allows for easy and rapid sample preparation and is therefore a potential candidate for simple and cost‐effective analysis. In this work, the TXRF‐Mo system was used for multielement analysis of the urine samples of 21 non‐professional athletes who ran a 53 km mountain ultra‐marathon. Urine samples were collected at four time points, at the beginning of the race (pre‐race samples), immediately, and 12 and 24 h post‐race. Al, As, Ba, Ni, Pb, Rb, Sr, V, and Tl were detected in the collected urine samples. The accuracy and precision of the proposed methods were verified by the analysis of reference materials (Seronorm™ Trace Elements Urine Level 2). The TXRF results were in agreement with the reference values and no significant differences were observed at the 95% confidence level. The detection limits for the elements of interest were also reasonable considering their concentration ranges in real samples. Changes were observed over time with increasing average urinary metals and metalloids levels, but only two significant results, were an increase in As and Rb. The results indicate a high degree of inter‐subject variability. The results obtained show that the content of toxic metals and metalloids increases in the urine samples collected after the race, which could confirm the statement that physical activity can increase the excretion of toxic metals and metalloids from the body. The simplicity of the TXRF method as well as its fast performance make it suitable for routine analysis.

Can amine ligands atomically disperse Cu atoms on TiO2(110)? Cu deposition on TiO2(110) premodified with o-anthranilic acid

Abstract The three-dimensional (3D) structure of evaporated Cu atoms on a TiO2(110) surface premodified with o-anthranilic acid (o-AA) was examined using polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS) to elucidate the effect of the premodification on the Cu dispersion over the TiO2(110) surface. Cu was found to be atomically dispersed with the formation of N–Cu–O bonds (where the N is provided by the o-AA and the O is present in the TiO2 lattice) on the surface, and the factors for controlling the atomic dispersion are discussed.

Ultrasensitive determination of selenium in food samples and its speciation in water and beverages using thiosemicarbazide-incorporated graphene and total-reflection X-ray fluorescence spectrometry

The paper presents a new analytical procedure for the determination and speciation of trace and ultratrace selenium in water, beverages, seafood, milk, and vegetables. The developed method is based on the dispersive micro-solid phase extraction with the use of new thiosemicarbazide-incorporated graphene as a solid sorbent, in combination of the total-reflection X-ray fluorescence spectrometry (TXRF). As a result, we have created an auspicious analytical tool for fast and sensitive analysis of samples with a complex matrix. Regardless of the specimen type, the method is characterized by a very low detection limit of 1.7 pg mL−1 and high precision. The developed strategy allowed us to solve common problems associated with selenium loss during the sample preparation for the TXRF measurement and also improve its performance toward the analysis of beverages and high saline/solid samples, which may even be impossible to perform using standard sample preparation procedures for a TXRF measurement.

Phenotypic Diversity and Genetic Parameters of Coffea canephora Clones

The simultaneous analysis of the maximum number of chemical elements present in plant tissues provides more comprehensive information about their chemical constitution and increases the number of characteristics for the selection process in various plant breeding programs. The objective of this study was to analyze productivity, grain yield, and concentration of chemical elements in tissues of Coffea canephora clones to study phenotypic diversity and estimate genetic parameters for use in breeding. This experiment was carried out in Manaus, Amazonas, Brazil, in randomized blocks with four replications. The concentrations of elements in various organs were quantified using total reflection X-ray fluorescence (TXRF). Genetic parameters and genetic divergence were estimated, and genotypes were clustered using the UPGMA hierarchical method and non-metric multidimensional scaling analysis. The study allowed us to differentiate the performance of the clones in terms of the absorption of essential and non-essential chemical elements for plant development and to analyze the correlation of the characteristics in the selection process. TXRF efficiently characterizes the presence and concentration of multiple elements, aiding genotype discrimination for C. canephora improvement.

Effect of sample carriers on analytical parameters in total reflection X-ray fluorescence - a tool for multi-trace elemental analysis

The Total reflection X-ray Fluorescence technique is increasingly popular for its simplicity and rapid elemental screening. This study evaluates the various analytical parameters including spectroscopic resolution, absolute sensitivity, relative element sensitivity, lowest limits of detection, accuracy and precision of the Total reflection X-ray Fluorescence spectrometer. This evaluation is conducted using quartz and acrylic sample carriers with mono and multi-element standards. Notably, the quartz sample carrier demonstrated excellent values of spectroscopic resolution, absolute sensitivity, the lowest limits of detection, a recovery rate of 90–110% and a coefficient of variation of 3–6% for the quantified elements from mono and multi-element standards. These findings underscore the robust analytical capability of the Total reflection X-ray Fluorescence technique for multi-trace elemental analysis. This research article not only provides practical and straightforward guidelines for handling Total reflection X-ray Fluorescence spectrometer but also confirms the practicality and effectiveness of the sample carriers for rapid and reliable elemental screening applications.

Titanium dioxide release behavior during wash of UV-protective garments by total reflection X-ray fluorescence

The increasing worldwide use of different kinds of clothes with ultraviolet protection in recent years, in particular employing titanium dioxide nanoparticles, is driving the researchers’ attention to the possible environmental problems due to titanium release. This study aims at determining the amount of titanium released from seven ultraviolet-protective garments into the wash water employing total reflection X-ray fluorescence spectrometry. For this, a wash protocol was designed based on the international standard ISO 105-C06:2010 and the literature. Pieces (4 cm × 10 cm) of textile were sampled from the garments and submitted 30 times to the wash protocol. The wash water produced in each wash was then prepared for total reflection X-ray fluorescence analysis. Results showed that the titanium released in 30 washes was between 8.6 ± 1.3 µg/L and 168 ± 3 µg/L. Every sample released titanium in the first to third wash, except sample 1, which first released titanium in the 18th wash. The greatest titanium release in one single wash was also the 18th wash of sample 1, which released 77 ± 2 µg/L. These results showed the good performance of total reflection X-ray fluorescence spectrometry in quantifying low titanium amounts in wash water, which is a hard task even for well-established analytical methods.

X-Ray Fluorescence Spectrometry: Current Status and Prospects of Development

This review covers characteristics and potential applications of various versions of the X-ray fluorescence (XRF) spectrometry for analyzing both liquid and solid samples. Particular emphasis is given to research published within the past decade, as information on XRF’s previous applications can be found in earlier reviews and monographs. The results of experiments on determining fundamental atomic parameters, such as mass absorption coefficients, fluorescence yields, transition probabilities for the emission of specific lines of elements, and nonradiative transition probabilities. Additionally, the review addresses the capabilities of newly designed models of XRF spectrometers developed in recent years. The application of total reflection X-ray fluorescence spectrometry for diverse samples is examined in greater detail. Furthermore, the document presents data on the utilization of XRF in investigating nanoparticles of some typical materials. These particles exhibit qualitatively novel properties and have become a focal point of nanotechnology, an area rapidly developing in the last few decades.

Geochemical contamination of heavy metals and health risk assessment of coastal sediments along the North Chennai to Pondicherry, India using total reflection X-ray fluorescence spectroscopy (TXRF)

The present work aimed to assess the contamination and human health risk assessment of heavy metals (HMs) in 21 sediment samples collected from the North Chennai to Pondicherry coastal area of Tamil Nadu using total reflection X-ray fluorescence spectroscopy (TXRF). Enrichment factor (EF), contamination factor (CF), and geo-accumulation index (Igeo) were calculated to estimate sediment contamination. The average concentrations of HMs (mg kg−1 dry weight) were: Al (4305.12), V (25.77), Cr (15.08), Mn (83.39), Fe (4539.77), Ni (2.89), Cu (2.67), Zn (9.46), As (2.81), Hg (0.05), and Pb (0.92). Results of EF indicated no enrichment with Al, Ni, and Pb, moderate enrichment with V, and severe enrichment with As and Hg. Based on Igeo, all sediment samples showed unpolluted with HMs (except As and Hg). Based on total lifetime cancer risk (LCR), there are no significant health risks for people in the study area from carcinogenic Cr, As, and Pb.

Ketogenic diet influence on the elemental homeostasis of internal organs is gender dependent

The ketogenic diet (KD) is a low-carbohydrate and high-fat diet that gains increasing popularity in the treatment of numerous diseases, including epilepsy, brain cancers, type 2 diabetes and various metabolic syndromes. Although KD is effective in the treatment of mentioned medical conditions, it is unfortunately not without side effects. The most frequently occurring undesired outcomes of this diet are nutrient deficiencies, the formation of kidney stones, loss of bone mineral density, increased LDL (low-density lipoprotein) cholesterol levels and hormonal disturbances. Both the diet itself and the mentioned adverse effects can influence the elemental composition and homeostasis of internal organs. Therefore, the objective of this study was to determine the elemental abnormalities that appear in the liver, kidney, and spleen of rats subjected to long-term KD treatment. The investigation was conducted separately on males and females to determine if observed changes in the elemental composition of organs are gender-dependent. To measure the concentration of P, S, K, Ca, Fe, Cu, Zn and Se in the tissues the method of the total reflection X-ray fluorescence (TXRF) was utilized. The obtained results revealed numerous elemental abnormalities in the organs of animals fed a high-fat diet. Only some of them can be explained by the differences in the composition and intake of the ketogenic and standard diets. Furthermore, in many cases, the observed anomalies differed between male and female rats.

Total Reflection X-ray Fluorescence Spectrometric Analysis of Ten Lanthanides at the Ultratrace Level Having a High Degree of Overlap in the Emission Lines.

The extensive use of lanthanide elements in the medical, electrical, agricultural, and nuclear fields has increased their contamination in the environment. The detrimental effect of lanthanides on human health can be reduced or eliminated by their fast determination in the concerned specimen. For this purpose, an offline conjugation of the cloud point extraction (CPE) process with total reflection X-ray fluorescence (TXRF) spectrometry was done. This process was found to provide simple, quick, and precise simultaneous determination of ten lanthanides whose emission lines have a high degree of overlap at the ultratrace level. N,N,N',N'-tetra-octyl-diglycolamide in triton X-114 micelles was found to offer a selective CPE of all of the lanthanides in the presence of higher concentrations of naturally abundant cations and anions. A multivariative partial least-squares regression (PLSR) calibration approach was preferred due to the complex overlapped spectra of L lines of the lanthanides. Ten lanthanides, viz., La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, and Lu, were simultaneously determined by this method, having concentrations in the range from 10 to 5 × 103 μg L-1. The proposed method was validated by analyzing three certified reference materials (CRMs), viz., NASS-7 seawater, SRLS-6 river water, and NIST 1640a natural water, via standard addition with the relative standard deviations of ≤10%.

Combining molecular dynamics simulations and x-ray scattering techniques for the accurate treatment of protonation degree and packing of ionizable lipids in monolayers.

The pH-dependent change in protonation of ionizable lipids is crucial for the success of lipid-based nanoparticles as mRNA delivery systems. Despite their widespread application in vaccines, the structural changes upon acidification are not well understood. Molecular dynamics simulations support structure prediction but require an a priori knowledge of the lipid packing and protonation degree. The presetting of the protonation degree is a challenging task in the case of ionizable lipids since it depends on pH and on the local lipid environment and often lacks experimental validation. Here, we introduce a methodology of combining all-atom molecular dynamics simulations with experimental total-reflection x-ray fluorescence and scattering measurements for the ionizable lipid Dlin-MC3-DMA (MC3) in POPC monolayers. This joint approach allows us to simultaneously determine the lipid packing and the protonation degree of MC3. The consistent parameterization is expected to be useful for further predictive modeling of the action of MC3-based lipid nanoparticles.

Total Reflection Xray Fluorescence (TXRF) spectrometry as a powerful and broad-spectrum analytical tool in the nuclear sciences

X-ray spectroscopy is widely used in nuclear reaction and structure studies. To aid such studies the technological envelope is continually being pushed to achieve higher quality such as superior power and brilliance, higher resolution and sensitivity. We present the discussion of a relatively new form of X-ray fluorescence spectrometry - Total Reflection X-ray Fluorescence (TXRF) spectrometry that can achieve analytical sensitivities of the order of parts per billion (ppb). An overview of the TXRF technique is presented and its utility for nuclear materials analysis discussed. Polarized Energy Dispersive X-ray Fluorescence (PEDXRF) spectrometry is also an XRF technique that can complement TXRFS where it may not be applicable. That scenario is discussed with respect to our results using PEDXRF on geothermal samples that serve to corroborate the recent findings of the Borexino Geoneutrino Experiment regarding the high Th, U concentrations in the earth’s mantle.